A conventional knuckle arm 30 for vehicles is shown in FIG. 5 and generally includes a bearing hole 31 defined in a radial direction thereof. The bearing on a drive shaft is received in the bearing hole 31, and a wheel 32 is connected to the drive shaft. A pull rod 33 integrally extends from the knuckle arm 30 so as to turn the wheel 32. A connection hole 34 is defined in the knuckle arm 30 and located beside the bearing hole 31 so that a joint 35 on a control arm is pivotably connected thereto. However, because the pull rod 33 is integral with the body of the knuckle arm 30, the orientation of the pull rod 33 relative to the body of the knuckle arm 30 is strictly limited when connecting the wheel 32 on different positions of the vehicle. In other words, the length of the pull rod 33 and the direction that the pull rod 33 extends for front and rear wheels are different. This requires different sets of molds to manufacture these knuckle arms 30. Further, some brands of vehicles are front drive vehicles, and some are rear drive vehicles. Thus, the positions of the bearing holes 31 may vary according to the vehicles.
The present invention intends to provide a knuckle arm that can be used for both left and right wheels and where the pull rod is removably connected to the knuckle arm so that the cost of the mold for manufacturing the knuckle arms can be reduced.